1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

Participatory catchment rehabilitation (Participación comunitaria para la rehabilitación … [Peru]

Promoting the rehabilitation of ancient terrace systems based on a systematic watershed management approach.

• Compiler: Philippe Zahner
• 01/16/2009 midnight

2.1 Short description of the Technology

Definition of the Technology:

Repair of ancient stone wall bench terraces, and of an associated irrigation and drainage system.

2.2 Detailed description of the Technology

Description:

The level bench terrace system in the Colca valley of Peru dates back to 600 years AD. Since then the terraces have been continuously used for crop production, but due to lack of maintenance they have deteriorated, and the population has lost its traditional knowledge of repair.
The rehabilitation of the terraces recreates their original structural design. Broken sections are cleared and the various materials - stones, topsoil, subsoil and weeds - are removed and separated. The foundation is re-established, followed by construction of the stone wall (the ‘riser’). Backfilling with subsoil then takes place; this is consolidated and finally covered with topsoil. Simultaneously the complementary irrigation and drainage systems are reconstructed.
The rehabilitated terraces efficiently conserve soil and water on steep slopes, and they create a favourable microclimate for crops, reducing loss of stored heat at night by minimising air movement (preventing frosts) and mitigating dry conditions through moisture conservation. The main economic benefits are from increased yields and crop diversification.
Terraces are spaced and sized according to slope, eg on a 50% slope, terraces are 4 m wide with a 2 m high riser between terrace beds. Stones of ancient terraces had been widely used to build walls for boundary marking after privatisation of land, therefore a large amount of stone had to be provided by splitting rocks and transporting from other locations.
The area is characterised by steep slopes with loamy-sandy, moderately deep soils (on the terrace beds). Most of the annual precipitation (ca. 350 mm) falls within a period of 3 months, which makes irrigation necessary. The farmers in the area own, on average, 1.2 hectares of arable land, divided into around six plots in different agro-ecological zones. Production is mainly for subsistence. Important supportive technologies include agronomic measures such as improved fallow, early tillage, ridging, and intercropping. Tree and shrub planting at the base of terrace walls is an optional measure with the aim of stabilising the walls, diversifying production and again ensuring a good microclimate. On average 250 trees/ha are planted; these are mainly native species such as c’olle (Buddleia spp.), mutuy (Cassia sp.), molle (Schinus molle: the ‘pepper tree’) and various fruit trees including capulí (Prunus salicifolia).

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

Country:

Peru

Region/ State/ Province:

Río Colca,Caylloma, Arequipa

Comments:

Total area covered by the SLM Technology is 100 km2.

Map

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2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through projects/ external interventions

3.1 Main purpose(s) of the Technology

• improve production
• reduce, prevent, restore land degradation
• create beneficial economic impact

3.2 Current land use type(s) where the Technology is applied

Cropland

• Annual cropping

Annual cropping - Specify crops:

• cereals - maize
• fodder crops - alfalfa
• legumes and pulses - beans
• root/tuber crops - potatoes

Specify:

Longest growing period in days: 120 Longest growing period from month to month: Dec - Apr

Grazing land

Intensive grazing/ fodder production:

• Cut-and-carry/ zero grazing

Comments:

Main crops (cash and food crops): Major food crop: Potatoes, maize,beans, etc
Main animal species and products: Alfalfa (cut and carry)

Major land use problems (compiler’s opinion): - Loss of productive capacity: 30% of the agricultural land lost due to degraded terraces, severe deforestation (through
cutting for fuelwood), overgrazing and burning of grazing areas.
- Inefficient irrigation practices (flooding) due to poor maintenance of irrigation system (and drainage system in poor
condition), flood irrigation leads to deterioration of terraces.
- Loss of traditional knowledge of ancestral crop management practices (abandonment of appropriate rotation practices, lack of residue incorporation/recycling, unsystematic crop layout).

3.4 Water supply

Comments:

Water supply: mixed rainfed - irrigated and rainfed

3.5 SLM group to which the Technology belongs

• cross-slope measure
• irrigation management (incl. water supply, drainage)
• water diversion and drainage

3.6 SLM measures comprising the Technology

structural measures

• S1: Terraces

Comments:

Main measures: structural measures

Secondary measures: agronomic measures, vegetative measures

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

• Wt: loss of topsoil/ surface erosion
• Wg: gully erosion/ gullying

chemical soil deterioration

• Cn: fertility decline and reduced organic matter content (not caused by erosion)

water degradation

• Ha: aridification

Comments:

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Wg: gully erosion / gullying, Cn: fertility decline and reduced organic matter content, Ha: aridification

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• restore/ rehabilitate severely degraded land

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Rehabilitated ancient terraces with high stone risers. Two options for irrigation and drainage of excess water are shown: outlets in the risers (left) and a broad water channel cutting perpendicularly through the terraces (right).

Technical knowledge required for field staff / advisors: high

Technical knowledge required for land users: moderate

Main technical functions: control of dispersed runoff: retain / trap, reduction of slope angle, reduction of slope length, increase of infiltration, water harvesting / increase water supply, improvement of microclimate

Secondary technical functions: control of dispersed runoff: impede / retard, control of concentrated runoff: impede / retard, increase in organic matter, increase / maintain water stored in soil, sediment retention / trapping, sediment harvesting, improvement of soil structure

Author:

Mats Gurtner

4.3 Establishment activities

4.4 Costs and inputs needed for establishment

4.5 Maintenance/ recurrent activities

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)

Comments:

Machinery/ tools: A-frame,tape measure,motor drill,wheelbarrow,shovel,pick,steel bar,sledgehammer,hoe,hand compressor.

Person days needed for rehabilitation of 1 ha of ancient terrace system depend on degree of deterioration, the dimensions of the wall, slope angle (the steeper the more terraces) and availability of stones. In the case of the project, under a typical situation, for physical rehabilitation of 1 ha with 6 terraces, each ca 600 m long, 3–4 m wide and 2 m high, with one third of the main structures in disrepair, 18 men and 7 women work for 5 days; shrub planting is extra. Land users bear 35% of the overall costs: they also provide food for the group during work. The programme pays the rest. 450 m3 of additional stones are required to repair the broken parts, the cost includes blasting/splitting rocks and transport to the construction site.
Supportive agronomic measures and agricultural inputs (seeds and manure) are not included. Maintenance costs vary considerably, depending on the specific situation: an average is taken here.

5.1 Climate

5.2 Topography

Comments and further specifications on topography:

Landforms: Also hill slopes (ranked 2) and footslopes (ranked 3)
Slopes on average: Also hilly (ranked 2) and rolling (ranked 3)

5.3 Soils

If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil fertility: Medium (ranked 1, used for maize) and low (ranked 2)
Topsoil organic matter: Low (low recycling of organic matter)
Soil drainage/infiltration: Medium

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Off-farm income specification: main source is wage labour in the valleys
Market orientation of grazing land production system: Subsistence (ranked 1) and mixed (ranked 2, 30% for market)
Market orientation of grazing land production system: Subsistence (ranked 1, complementary to crop production) and commercial/market (ranked 2, income generation to meet basic needs)

5.7 Average area of land used by land users applying the Technology

5.8 Land ownership, land use rights, and water use rights

Land ownership:

• individual, not titled
• individual, titled

Land use rights:

• leased
• individual

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Other socio-economic impacts

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

Other ecological impacts

6.2 Off-site impacts the Technology has shown

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

6.5 Adoption of the Technology

If available, quantify (no. of households and/ or area covered):

240

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?

• 11-50%

Comments:

90% of land user families have adopted the Technology with external material support

2160 land user families have adopted the Technology with external material support

10% of land user families have adopted the Technology without any external material support

240 land user families have adopted the Technology without any external material support

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: There is a moderate trend towards spontaneous adoption.
40% of terraces have been rehabilitated in 7 districts (8 micro-watersheds) of the Colca valley.

6.7 Strengths/ advantages/ opportunities of the Technology

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Mejia Marcacuzco AP Folleto de divulgación: Andenes, construcción y mantenimiento. (undated).

Title, author, year, ISBN:

Treacy, JM (undated) LasChacras de Coporaque: Andenes y riego en el valle del Colca. Instituto de Estudios Peruanos. DESCO